FROM THIS EPISODE

Is the US hoping to overthrow the current leaders of Iran's Islamic Republic? If those leaders believe that, will they be more likely than ever to develop a nuclear bomb? Will tough talk in the presidential campaign convince them there's no other choice? Also, the video of US Marines urinating on dead Taliban fighters, and more on 200 pardons by Mississippi's outgoing Governor Haley Barbour. Does his explanation make sense in a state notorious for locking up suspects based on false evidence?

Banner image: Iranian security forces inspect the site where a magnetic bomb attached to a car by a motorcyclist exploded outside a university in Tehran on January 11, 2012, killing a scientist and injuring two other people, according to Iranian news agencies. Photo by Sajad Sfari/AFP/Getty Images

A video that appears to show four US Marines urinating on the bodies of dead militants in Afghanistan has gone viral, condemned by Defense Secretary Leon Panetta and Afghan President Hamid Karzai. Will it turn the Afghan public against the war effort? Julian Barnes reports from the Pentagon for the Wall Street Journal.

The US has categorically denied any role in yesterday's assassination of an Iranian nuclear scientist or the recent deadly attack on an Iranian missile facility, and says an attack on Iran is not inevitable. But two American aircraft carrier battle groups are near Iranian shores with a third on the way, and the Pentagon is making contingency plans in case Iran learns to make nuclear weapons. Diplomacy is the official policy, but the US is imposing new sanctions that could do real damage to Iran's oil economy, and State Department officials say they're "tightening the noose." If Iran's rulers think America's goal is regime change, will they be more likely to develop atomic bombs for their own protection? Is anti-Iranian rhetoric by Republican candidates pushing the President to take a harder line that will make confrontation more likely than diplomacy?

Mississippi's former Governor Haley Barbour waited two days before explaining why he pardoned 200 convicts before leaving office this week. He said most already had been released and that all deserved the right to get jobs, vote and be licensed to hunt. But a judge blocked more than 21 pardons and four convicted killers may have to go back to jail. Judge Tomie Green agreed with an outraged Mississippi Attorney General Jim Hood that some may have violated the state constitution, which requires a notice of possible pardons be published in local newspapers for 30 days. Tucker Carrington is Director of the Mississippi Innocence Project, based at the University of Mississippi School of Law.